testdisk/src/file_evtx.c
2021-06-08 13:54:30 +02:00

90 lines
3 KiB
C

/*
File: file_evtx.c
Copyright (C) 2019 Christophe GRENIER <grenier@cgsecurity.org>
This software is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License along
with this program; if not, write the Free Software Foundation, Inc., 51
Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
*/
#if !defined(SINGLE_FORMAT) || defined(SINGLE_FORMAT_evtx)
#ifdef HAVE_CONFIG_H
#include <config.h>
#endif
#ifdef HAVE_STRING_H
#include <string.h>
#endif
#include <stdio.h>
#include "types.h"
#include "filegen.h"
#include "common.h"
struct evtx_header
{
char magic[8];
uint64_t OldestChunk;
uint64_t CurrentChunkNum;
uint64_t NextRecordNum;
uint32_t HeaderPart1Len; /* 0x80 */
uint16_t MinorVersion; /* 1 */
uint16_t MajorVersion; /* 3 */
uint16_t HeaderSize; /* 0x1000 */
uint16_t ChunkCount;
char unk[76]; /* 0 */
uint32_t Flags;
uint32_t Checksum;
} __attribute__ ((gcc_struct, __packed__));
/*@ requires valid_register_header_check(file_stat); */
static void register_header_check_evtx(file_stat_t *file_stat);
const file_hint_t file_hint_evtx= {
.extension="evtx",
.description="Microsoft Event Log",
.max_filesize=PHOTOREC_MAX_FILE_SIZE,
.recover=1,
.enable_by_default=1,
.register_header_check=&register_header_check_evtx
};
/*@
@ requires buffer_size >= sizeof(struct evtx_header);
@ requires separation: \separated(&file_hint_evtx, buffer+(..), file_recovery, file_recovery_new);
@ requires valid_header_check_param(buffer, buffer_size, safe_header_only, file_recovery, file_recovery_new);
@ ensures valid_header_check_result(\result, file_recovery_new);
@ assigns *file_recovery_new;
@*/
static int header_check_evtx(const unsigned char *buffer, const unsigned int buffer_size, const unsigned int safe_header_only, const file_recovery_t *file_recovery, file_recovery_t *file_recovery_new)
{
const struct evtx_header *hdr=(const struct evtx_header *)buffer;
if(le32(hdr->HeaderPart1Len) != 0x80 ||
le16(hdr->MinorVersion) != 1 ||
le16(hdr->MajorVersion) != 3 ||
le16(hdr->HeaderSize) != 0x1000)
return 0;
reset_file_recovery(file_recovery_new);
file_recovery_new->extension=file_hint_evtx.extension;
file_recovery_new->calculated_file_size=(uint64_t)le16(hdr->HeaderSize) + (uint64_t)le16(hdr->ChunkCount) * 64 * 1024;
file_recovery_new->data_check=&data_check_size;
file_recovery_new->file_check=&file_check_size;
return 1;
}
static void register_header_check_evtx(file_stat_t *file_stat)
{
register_header_check(0, "ElfFile", 8, &header_check_evtx, file_stat);
}
#endif